SOLAR SYSTEM

Detailed explanation-1: -The first passive satellite transponder was developed and launched by the United States in 1960. The satellite, known as Echo 1, was a large metallic balloon that was able to reflect radio signals back to Earth. The Echo 1 satellite was launched into a low Earth orbit and had a diameter of approximately 100 feet.

Detailed explanation-2: -The term “satellite transponder” refers collectively to a transmitter-receiver subsystem on board the satellite that processes, amplifies and retransmits a range of frequencies (the transponder bandwidth) to another location/terminal/antenna on the earth.

Detailed explanation-3: -Basically, there are two types of transponders. Those are Bent pipe transponders and Regenerative transponders.

Detailed explanation-4: -Sophisticated active transponders are used in communications satellites and on board space vehicles. They receive incoming signals over a range–or band–of frequencies and retransmit the signals on a different band at the same time.